It would seem, then, that my incorporation of mod_perl scripts into my web apps will need to depend on precisely on what I need to do.

I won't write off FastCGI, as, based on what I have been reading, I can write C++ programs and have them invoked by it. Thus, I ought to be able to use the C++ connector for my DB to make a connection (or connection pool), and then use my favourite C++ idioms to do one statistical analysis or another of the data retrieved from the DB, returning only the results of the analysis to the web page (and this probably mediated from a JavaScript AJAX call). I know this is a Perl forum, but the fact is that with some of the statistical analyses I do, I can get order of magnitude better performance from my best C++ code than I can with perl; and this makes some kinds of reporting within a web application feasible (in terms of a result in less than a minute VS a result in 20 minutes - I know I could implement my algorithms in C++ withn the bowels of a Perl module, but why, when the analyses are very specialized, and probably not particularly useful for anyone other than myself).

I guess at present my best options are to use mod_perl for some things and to change all my usages of DBI->connect(...) to DBI->connect_cached(...)